The peer-review process for the above article was found to have been compromised and inappropriately influenced by the first author, Yongdeng Lei. As a result the findings and conclusions of these articles cannot be relied upon.

The Editor-in-Chief was misled in believing that she had accepted the article based upon a favorable review. The article is retracted based upon violation of the integrity of the peer review process.

The first author and the publisher wish to retract this paper to preserve the integrity of material published in the journal. The publisher acknowledges that the integrity of the peer review process should have been subject to more rigorous verification to ensure the reviews provided were genuine and impartial. The publisher apologizes for any inconvenience rendered to the readers of the journal and wishes to assure the reader that measures have been taken to ensure that the peer review process is comprehensively checked to avoid a similar error occurring.